Cycling trainer



FIG. 1 is a front perspective view of an ornamental design for a cycling trainer;

FIG. 2 is a rear perspective view of the ornamental design;

FIG. 3 is a front elevation view of the ornamental design; and,

FIG. 4 is a rear elevation view of the ornamental design.

Broken lines in the illustrations of the drawing indicate unclaimed parts of the article that are not part of the design illustrated herein. 

CLAIM The ornamental design for a cycling trainer, substantially as shown and described. 